Inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase lower fecundity in the German cockroach: correlation between the effects on fecundity in vivo with the inhibition of enzymatic activity in embryo cells.

The enzyme 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase is crucial to insect development and reproduction, as revealed by the sterilising properties of some specific inhibitors of it. In the present paper, we study the sterilising effects of a number of HMG-CoA reductase inhibitors on the German cockroach, Blattella germanica (L). The inhibitors tested were naringenin, lovastatin, mevastatin, simvastatin, atorvastatin and fluvastatin. The first two compounds were ineffective or scarcely effective as HMG-CoA reductase inhibitors. The most active compounds in vivo were fluvastatin and atorvastatin, followed by simvastatin and mevastatin. They were equally ranked when tested as HMG-CoA reductase inhibitors in the B germanica embryonic derived cell line UM-BGE-1. This suggests that this cell line may be an appropriate tool for testing HMG-CoA reductase inhibitors and so to predict their properties as insect sterilising agents with insecticide potential.